Among all the Écrins valleys, the Séveraisse valley and its fast-flowing torrent cuts deepest into the heart of the range. The gateway for climbers setting out to tackle Les Bans, Olan, and other mythical summits over 3,000m, it is strewn in Himalayan-like stone fortresses. Everything is so wild and untamed that any sign of humankind in the Prentic meadows or the tiny isolated hamlets is almost endearing.